Improvement in apparatus for distilling oils



UNITED STATES PATENT CEETGE.

HERBERT W. e. TWEDDLE,l oE rIT'rsBUECf` PENNSYLVANIA.

IMPROVEMENT IN APPARATUS FOR DAISTILLING OILS.

Specification forming part of Letters Patent No. 72,125, dated December 10,1867.

To all whom 'it may concern.'

Be it known. that I, HERBERT IV. C. TWED- DLE, of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania, 'have invented a new and useful Improvement in Apparatus for Distillin g Oils; and I do hereby declare the following to be a full, clear, and eXact description thereof, reference bein g had to the accompanying drawing, making a part of this specification, in which- Figure 1 is partly a side and partly a sectional elevation of my improved apparat-us for distilling oil, and Fig. 2 is a rear end view of the same, partly in section.

Like letters of reference indicate like parts in each.

The nature of my invention consists, first, in the construction and arrangement of devices for promoting the evaporation of undistilled or reinable oils by passing the same continuously in a thin lm, layer, or stream, produced by dropping or otherwise, over a heated surface, or a succession of suchsurfaces, in a vacuum-still; second, in combining together two or more such stills in such a way that the heavier oils, which do not vaporize at the temperature to which they are raised in one still, shall be conveyed to another still, where they will', ,by the use `of similar devices,

be exposed to a higher degree of heat, and so on successively until only the residuum is left.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and how used.

O11 any suitable frame or foundation A, I place two or more stills or a battery of stills, B C, one, B, somewhat higher than the other, C, so that the oil may flow readily from at or near the bottom of one into the other, as yet to be described. In these stills I preserve a partial or complete vacuum by the use of an air-pump, or. in other known way, and connect them to the eondensers B2 G2 by the goose: necks Bl Cl respectively. Ineaeh ofthe stills B C is a series or coil of pipe, a, each pipe of the series or coil passing through the still horizontally, but one being arranged over the other in any desirable number of vertical rows, and

t joined together by a connection-pipe, d. Above each vertical row of such pipes a is placed a trough, a', which has small perforations in the sldes or bottom, as seen in Fig. 1, and a serrated edge, c, underneath. Below the lowest of series or coil of pipes a. is placed a series or coil of perforated pipes, c, `for admitting superheated steam, such pipes being joined together by a collinecting-pipe, d.

The crude petroleum is admitted, either cold or in a heated state, as may be deemed advisable, through a cock, b, at the side of the still B, into a pipe, b, which, running transversely across over the troughs a', discharges, through a perforation over each such trough, as shown in Fig. 2, the oil into such perforated and serrated troughs a. Through the perforations in each trough a the oil runs down, gathers ou the points of the serrated edges c, whence it falls onto the steam pipes a, dropping or running from pipe to pipe, and passing in a thin film over the surfaces of such pipes. A eurrent of dry or superheated steam, .passing in at the' valves :l: keeps such pipes a heated to a high temperature consequently the drops or streams of oil coming in contact with and passing over them are subject to the action of a heated surface relatively large, which causes it lto volatilize with great rapidity-the more i so as the pressure of the atmosphere is a1- ready removed from the inside of the still by the air-pump, as already stated. I also sometimes place a `serrated edge under each pipe a., similar to that shown at c, whereby the oil is more evenly distributed in its descent from pipe to pipe. The sheets or strips, the edges of which constitute the serrated edges o, whether on the troughs a. or )ie a ma extend v o l 1 7 downward, and come in contact with the pipe immediately under, so that the oil will run therefrom onto such pipe, instead of dropping', as above described; and in such case Vtwo such sheets or strips may be employed, one coming down so as to discharge the oil on each side of the topline of the surface of the pipe.

In the pipe c, for the admission of the superheated' steam, I make a number of jetholes,

through `which jets of superheated steam are discharged into the still in such way as to come in contact with the oil on the surface of the pipes a, andstill further promote their evaporation. Steam is admitted to the pipes c through the valves a w1. x2 1:2 are cocks through which to draw off the water formed by conldensation of the steam in the pipes a and e respectively. By the use of these devices the lighter or more volatile oils are driven off in the first still, B, in the form of vapor, which, being carried over by the goose-neck B1 tothe condenser B2, is there condensed, as presently to be described. Such of the heavier oils as are not thus vaporized in the rst still, B, fall.

.residuum, with the oils not yet volatilized, if

any, falls to the bottom lof the still C, whence 'it is conducted to another still and similarly treated, or, by a pipe, f', is discharged into a recelver, D, in which a vacuum is alsolpreserved..y From this it is drawn off by a cock,

g', at pleasure. A pipe, h, connects the receiver D with the still C, for convenience in securing a vacuum in the former and for the purpose of conducting over any vapors which may arise from the residual matter in such receiver.

The steam used in this process may be admitted into the pipes a and e'of each still separately, or it may be at first admitted into the' pipes a ande of the last and lowest of such stills, and conducted thence by 'pipes t i into the pipes a and e of the next still, and so on until the rst or highest still is reached. In this way I apply the steam when hottest to volatilizing the heavier oils, which, of course, require the greater degree of heat, and, as the temperature is reduced, apply it to driving 0E the lighter oils in the higher stills. Also,

, if the character of the oil is such that ahigher degree of heat is required or desired than dry or common steam will give out, I use superheated steam in they pipes ar as well as in the pipes e. l

As already stated, the vapors of volatilization in the still B pass by the goose neck l1 to the condenser B2, which is a combination of a surface and shower condenser.

TheV `condensing apparatus is the same for all the stills, and consists of a condensingchamber, C2, with cold-water chambers m m at either side, connected together by pipes a. The upper chamber, m, is perforated, as at o, so as to discharge jets of cold water into the con- .densingchambgr C2, to condense the oily vapors. Cold water is passed through pipes n for the same purpose. Water isadmitted and drawn off by the cocks s s. The condensed oil is drawn oft' at the cock s' with the condensed water, if there be any, and discharged into a tank or other receptacle.

The advantages of this process of distillation are, among others, rst,dispensing en tirely with the application of a fire orfire-heat to the stills or to the oil, whereby I avoid all possibility of a lire or of an explosiomwhich are the great sources of danger in distilling petroleum or hydrocarbon oils; second, collecting the vapors of the lighter and heavier oils and condensing them in separate receivers, whereby a quality of oil can be produced for illuminating purposes perfectly free from the volatile ingredients whichrender them dangerous in use at the temperatures to which, in such use, they are necessarily'raised; third, a cheaper process of distillation; and, fourth, the production of a better article. Another advantage arises from the fact that fluids in motion will evaporate more rapidly than fluids at rest, other things being equal.

It is not absolutely necessary that one still.

should be higher than another, since, by creating a more complete vacuum in the second still than in the first, and so on, the residual oil in the bottom of each stillmay be forced into the next at `the same or a higher level.

I do not limit myself in my invention to the particular form and arrangement of perforated and serrated pipes and troughs described, but include forms and arrangements of devices substantially similar, whereby the oil is caused to flow through notches, apertures, or perfora- Y tions in small quantities, and drop or run from both points `or projections onto and spread over the nheated surfaces of evaporating-pipcs in a vacuum-still. i

rIhe condensing-pipes n may be either vertical or horizontal, at pleasure.

It will be observed that the pipes h f', leading from the last still C to the receiver D, are provided with cocks z, by which communication between them is cut olf, in order to draw o' the contents of such receiver.

In addition to the uses above named, I apply my iuvention to the redistillation rof oil distilled by the ordinary process, by which I entirely avoid the expense and labor of refining, including the expense of acids, alkalies, &c., and at the same time produce an article more perfectly deodorized and otherwise of a superior character.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A trough or troughs having perforations for the passage of the oil in small quantities,

'and furnished with points near to such perforations, so as to cause the oil to pass' therefromv in drops or line streams, or thin films or layers, over heated pipes or tubes placed thereunder, when used within a vacuum -still, for the purposes substantially as described.

2. In a vacuum-still for distilling oil, the use of a series or coil of steam pipe placed horizontally, one under another, as a series. of

.evaporating-surfaces, substantially as and for the purposes above set forth.

3. In a vacuum still for distilling oil, a series or coil of steam-jet pipes, e, in combination with a series or coil of evaporating-pipes, a,

substantially as and for the purposes above set forth. f

- 4. Combining together a series of apparatus, such as hereinbefore described, lfor the purpose of procuring a continuous distillation of petroleum7 each member of a series consisting of a vacuum-still containing acoiiif steampipe as evaporating surfaces. and troughs for the gradual distillation of the oil, in combination Lwithsuitable condensing apparatus, substantially as and for the purposes hereinbefore set forth. 1

5. A vacuum residuum receiver, D, connected to and in combination with a vacuum- 

